1. Field of the Invention
The present invention relates to a method of reducing the amount of black in an image, such that a printer can print the image without or with only a little black ink (or toner).
2. Description of the Related Art
Generally, a common printer performs an automatic determination of an image for being printed according to a print command sent from a user end computer, after which it accordingly mixes in black ink (or toner) to achieve a grayscale effect, thereby saving the consumption of color ink (or toner) as well as achieving a better shadow detail effect. However, for certain situations, an image printed with black ink (or toner) is not desired. For example, when a user utilizes an optical pen (also known as an optical index/optical identification (OID) pen) to read a speech-purpose print code (mostly in the form of very tiny 2D barcodes) on a certain image, the efficiency of the OID pen may be affected if the image itself also contains a lot of black, since the speech-purpose print code is printed completely or primarily in black.
In known prior art solutions, image processing software is utilized to convert the image from an RGB format into a CMYK format and to eliminate or reduce the K value in the CMYK format. However, one RGB value may correspond to multiple CMYK combinations. Therefore, when the converted image is sent to a printer end, the printer system will still process the remaining CMY values, and add a K value to obtain a shadow effect. Moreover, the printed image may look unbalanced because the K value (i.e. the shadow) of the original image is eliminated, while the brighter part remains unchanged.
Therefore, there is a need to provide a method of reducing the amount of black so as to completely avoid the conversion mechanism of adding the K value performed by the printer system, such that the user can obtain a printed image without or with only a little black ink (or toner), thereby mitigating and/or obviating the aforementioned problems.